Bouncing along on horseback for a scene in the new flick that stars her as PRINCESS GRACE, NICOLE KIDMAN suddenly hopped off during a break – complaining that her bottom was tender because she hadn’t ridden in ages.

Then, as she bent to pick up a bottle of water, she suddenly screamed sharply, spewed a string of curses no princess should even know, and howled: “Ooooww…That horse just bit my bum!”

Insisting she was in too much pain to continue, Nicole limped to her dressing room to inspect the damage.

Luckily, the horse’s choppers hadn’t broken skin, but Pretty Redhead was now sporting a pretty nasty red mark.

Nicole finally agreed to remount her nippy steed, but this time a crew member held its head until her tempting butt was firmly in the saddle and out of striking distance!